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Friday, May 18, 2012

When is it OK to Stop Worrying About Bicycle Weight?

You might have noticed in my twitter updates that I recently bought a carbon fiber road bike to replace my heavier-than-most-steel-bikes Fuji Roubaix 3.0.  Honestly, my Fuji Roubaix 3.0 was a great bike, it just had some major drawbacks in race conditions.  Most of the problems involved the Sora groupset and the others involved the total weight and stiffness of the aluminum frame combined with a tiny... tiny bottom bracket shell.  I'll cover this in more detail with a full review on the Fuji Roubaix 3.0.


MY EXPERIENCE RACING ON A BIKE ~10 LBS HEAVIER THAN THE COMPETITION:
With one bottle, my Fuji Roubaix 3.0 weighed 27 pounds and 29 pounds for those two-bottle 50+ mile rides.  I was at a clear disadvantage compared to the full carbon frames about ten pounds lighter- forget grams!  Being as determined as I was to be competitive despite this handicap, I raced on this bike anyway because in my mind, weight didn't really matter on flats and descents- it really only mattered in the accelerations and climbs.

My race results seemed promising when I attended my first criterium and placed fourth in a citizens category.  However, after I bought a license and registered for my first Cat 5 race, my results were embarrassing and I quickly learned how much training I needed to just keep up.  Here are my racing results on my Fuji:

CAT 5 Results (Fuji Roubaix 3.0):
  • 07.16.2011 - Lapped by the group twice, max grade ~2%
  • 04.07.2012 - Lapped once, max grade ~2%
  • 04.15.2012 - Kept up for almost three laps with one major climb at 9% grade
What changed between 4/07 and 4/15?  I was finally able to add heavy weight lifting to my training program thanks to my new sponsor WeightVest.com.  Without access to a gym and being restricted to weight lifting in my apartment, I never had the chance to lift weights heavy enough that I could only complete a few repetitions... until now.  After lifting maximally for only one day with the 150 pound weighted vest that they sent me, I saw huge improvements.  It took a couple days of recovery (I needed it!), but once I was fresh and ready for an interval workout, I immediately noticed that I was climbing faster than I used to with significantly less fatigue.  Although I couldn't stick with the group throughout the entire race on 4/15, I couldn't believe that for almost three laps I was climbing and accelerating as fast as riders on 16-18 pound carbon bikes with super light/ aero Zipp wheels!  BIG thanks to WeightVest.com!

IS IT IMPOSSIBLE TO KEEP UP ON A 27 POUND BIKE?
If I could keep up for about half of a criterium on a 27 pound bike, then it's possible to train and develop enough strength to make up for the weight and stick with the guys in Cat 5.  No need for research to prove this since I've seen a friend of mine keep up and finish mid-pack on his mid 20 pound Trek!  When keeping up isn't enough, it will be time to consider a lighter bike, especially if you've already hit your optimal body weight.  This leads us to the following question:

HOW MUCH SHOULD I SPEND ON A CARBON FIBER BIKE?
While I shopped for a carbon fiber road bike, I asked myself if I should get one of the lightest carbon fiber road bikes on the market (15-16 pounds) or spend about $1k on a less popular/ less expensive carbon fiber road bike about 1 kilogram heavier than the top-of-the-line carbons.  To answer this question, I found a research study that fit this question to the T.  This study investigated the effects of adding 1 kg of weight to a bicycle on a cyclist's climbing performance.  While most of the subjects produced predictable results, the riders who weren't affected by the weight caught my eye.  Here's a summary of the article below:
ARTICLE SUMMARY: POWER DEVELOPMENT IN HILL CLIMBING AS A FUNCTION OF BICYCLE WEIGHT 
Problem:  The lack of studies investigating the effects of weight on climbing performance has made it difficult for competitive cyclists to quantify the benefits of riding a lighter bicycle uphill. 
Hypothesis:  By adding 1 kg of weight to the cyclist's bicycle, power output and the amount of time taken to reach the summit will increase, demonstrating the power-to-weight phenomenon- a limiting factor in athletic performance. 
Methods:  Thirteen cyclists ranging from Cat 1 to Cat 5 were used in this study.  They performed two rides separated by 30 minutes of rest- one without the weight and one with the 1 kg weight added to their bike.  Rest methods were not controlled- all riders were allowed to do whatever they preferred for recovery throughout the 30 minute time period.  The course was a 1.78 mile climb with an average and max grade of 16.47% and 18%, respectively.  To prevent the cyclists from knowing whether or not the weight was added to their bike, the weighing order was randomized.  Power, torque, speed and cadence was measured with a Saris PowerTap SL 2.4 (measures power at the rear wheel).   
Discussion of Results and Conclusion:
The results showed an average increase in maximum wattage and total time, but a decrease in average wattage.  The reason for the decrease in average wattage may be due to the short duration of the rest period and not an increase in efficiency.  Considering that the climb was performed maximally, the short rest period may have negatively affected their ability to sustain a high power output throughout the climb.  While most of the subjects demonstrated similar responses to the added weight, some of the riders produced unexpected results. Two riders demonstrated a decreased maximum power output and one rider reached the summit faster after adding 1 kg to the bike.  Here are the averaged results after adding 1 kg to bike:
  • Maximum Wattage Output: Increased an average of 53.77 watts +/- 38 watts.
  • Time to Completion: Increased 21 seconds
  • Average Power Output: Decreased 3.46 watts +/- 2.45 watts
CAN ADDING 2.2 POUNDS MAKE YOU FASTER & MORE EFFICIENT???
For subject #3 (CAT1), this seemed to be the case.  After adding 1 kg, subject #3 shaved 50 seconds off his time.  While I expected to see a much larger power output to compensate, he only increased his max and average watt output by 34 and 12 watts, respectively.  In terms of how much faster he reached the summit, this was a relatively small increase.  With only 30 minutes to rest, it's reasonable to question if similar results would have been produced if this rider performed the both trials without weight.  Does subject #3 have immune-to-weight super powers?

It might be a more appropriate question to ask at what point does bicycle weight play an insignificant role in cycling performance?  It seems to depend heavily on the fitness level of the cyclist.  The only information provided in the article that gave me a good picture of each cyclist's fitness level is that they all met the following criteria to participate in this study.
  1. All subjects trained at least 8 hours a week
  2. All subjects trained at high intensities for the last 1.5 years
Did they spend the eight hours working on intervals, slow/ fast cadence training, weight lifting and flexibility exercise?  We also don't know if the riders are specialists in solo time trials, team time trials, mountain biking, criteriums, track and stage races.  When the list above is the only information available to us, all we can really do is make some assumptions to get a better profile of the riders.  Since we know that subject #3 was a Cat 1 rider, the first assumption we can make is that he probably followed the progression below:
  • Cat 5 to Cat 4:  He finished 10 mass-start races.
  • Cat 4 to Cat 3:  Earned 20 or 30* points within a 12-month period OR has experience in 25 qualifying races with a minimum of 10 top ten finishes with fields of 30 riders or more OR had 20 pack finishes with fields over 50
  • Cat 3 to Cat 2:  Earned 25 or 40* points within any 12-month period
  • Cat 2 to Cat 1:  Earned 30 or 50** points within any 12-month period **10 of the points may be earned in races that are part of a training series or may be earned in master's races
To make sense of the points and gain a better understanding of how difficult it is to progress to Cat 1, check out the points charts from the USAC rulebook.  A Cat 1 rider must have several top finishes in criteriums, road races and stage races to get to this level.

Does this mean that all you have to do is race and win a lot to reap these immune-to-weight benefits?  Not exactly.  The winner of a race isn't always the strongest rider- the team, peloton and course can set a weak rider up for a victory.  Based on the data, we can't assume that all Cat 1 cyclists are unaffected by extra weight.  In fact, a Cat 1 rider also produced the worst time to reach the summit.  What variable are we missing?  Power to weight ratio and VO2 max.

While a cyclist can have an impressive power to weight ratio, a weak VO2 max can make climbing difficult.  This takes us to the next assumption, subject #3 must be either a medium to small size rider.  Since this study tested cyclists in climb-only conditions, it's safe to assume (based on field data) that with equal power to weight ratios, the medium to small rider has a clear advantage over larger riders due to their higher VO2 max numbers (2).  Remember that VO2 max is measured in ml/kg/min- so if body weight goes down, VO2 max will go up.

I'm not sure why comparative studies tend to use descriptive words like medium or small instead of weight, but I'll try to define it.  Using the competitive riders from the Tour de France as a scale, you'll find that some of the lightest riders are around 130 pounds and the heaviest riders are around 180 pounds and above...  so a medium rider would be around 155 pounds?  I know this isn't the most scientific method, but it better than just saying small or medium!

WHAT DOES IT TAKE TO BE "IMMUNE" TO A 1 KG WEIGHT VARIANCE?
Based on my observations of the data, the following qualities may help a cyclist develop the physiology necessary to resist being affected by a slightly heavier bicycle:
  • A medium (155 lbs) to small (130 lbs) build to improve VO2 max
  • A training program emphasizing on maximizing the cyclist's power to weight ratio- power training, weight lifting, power lifting, core strengthening, etc.
  • A training program emphasizing on maximizing the cyclist's VO2 max- overreaching endurance rides, recovery rides, aerobic/ lactic acid training, etc.
Based on the data, it appears that you don't have to be a Category 1 cyclist.  If you take a look at the table, you'll notice that cyclists of varying categories almost reach the point of performing upredictably well just like subject three.  A good number of the riders also demonstrated a small change in max or average watts and only a small increase in time which again, may be caused by the short rest period.  Here's a table showing the differences between the two trials, weighted and unweighted.  Enjoy!


SubjectCategoryDifference
#1 to 5Max WattAvg WattTime (sec)
142-128
218-767
313412-50
4571230
52102511
64-3-5759
74269711
84-95-1149
943-1247
104314125
1119755
12294012
135-133111

While I haven't found the research to support this, it's not unreasonable to say that a well balanced training program can help develop immune-to-weight powers.  Look for your weaknesses and make sure you covered everything in the areas of flexibilitystrength and endurance.  In my case, my program lacked the intensity to develop the appropriate training adaptations from strength/ power lifting since I didn't have access to heavy weights.  Learn from my mistake... don't wait to get the proper equipment for weight lifting!


BACK ON TOPIC: HOW MUCH SHOULD YOU SPEND ON A CARBON FIBER BIKE?
Since my optimal weight is below the 155 pound mark, I decided to save my money and buy the least expensive carbon road bike I could find which also tends to be the heaviest carbon fiber road bike on the market.  That's how I ended up with a Kestrel Talon carbon fiber road bike (price matched to $1299) weighing in at a hefty 18.6 pounds (without pedals) or 19.2 pounds (with pedals).  By continuing to work on improving my power output and VO2 max, it shouldn't matter that my Kestrel Talon is a little over 2 pounds heavier than the competition.  To put my theory to the test, I signed up for a 28 mile Cat 5 road race at Winona Lake.
  1. Wood, Brandon. "Power Development in Hill Climbing as a Function of Bicycle Weight." The University of Wisconsin-Whitewater 1 (2007): 1-18. Print.
  2. DP, Swain. "The influence of body mass in endurance bicycling."Medicine and science in sports and exercise 26.1 (1994): 58-63. Print.